The invention relates generally to snow plows for mounting on trucks and the like and specifically to a snow plow having a side gate controlling the off-flow of snow into abutting streets and driveways.
It is common practice to remove snow from streets through the use of an angled snow plow blade which channels snow from an area in front of a truck toward a curb side of the blade where the snow is deposited as a ridge running along the curb.
The angled plow, by spreading the removed snow in the ridge at the curb eliminates the need to haul the snow away. The snow ridge so formed at the side of the street is generally unobjectionable except where it blocks off adjoining streets, private drives or cross walks. The snow ridge may also cover fire hydrants. In these cases, time consuming and expensive additional steps must be taken to clear the blockage.
In order to prevent the formation of the snow ridge at certain points along the path of the snow plow blade, it is known to install a gate at the trailing edge of the snow plow blade. The gate may be closed to momentarily retain snow on the snow plow blade, stopping the formation of the offending snow ridge that may block streets or walks.
In one such approach, exemplified by U.S. Pat. No. 3,422,552, a side gate may be extended forward from the trailing edge of the main plow blade. Forward extension of this retaining gate allows the gate to immediately stop the small amount of snow flowing off the blade but to progressively handle the greater accumulation of snow over time as the side gate continues to extend forward. Likewise, as the gate is retracted in a rearward direction, the gradual retraction may evenly distribute the retained snow back into the ridge without dropping of a large block of snow in one location.
This forwardly extending side gate is not easily adapted to existing plow designs because it requires substantial additional mechanism to the side of the truck cab. Further, the side gate does not readily allow changes in angulation of the plow blade as may be required to adjust the plow to various snowfall conditions. Also, the tie rod 72 mounted to the front of the snowplow blade in U.S. Pat. No. 3,422,522 will break if the blade tips forward. Modern snowplow blades are designed to tip when they encounter road hazards such as utility hole covers, to avoid damage to the blade.